Matrix metalloproteinase 9 (MMP9) level and MMP9 -1562C>T in patients with obstructive sleep apnea: a systematic review and meta-analysis of case-control studies

Serum matrix metalloproteinase-9 as a potential biomarker for obstructive sleep apnea severity

PURPOSE

We aimed to investigate the associations between serum matrix metalloproteinase (MMP)-2 and MMP-9 levels and obstructive sleep apnea (OSA) severity with a focus on nocturnal hypoxemia.

METHODS

The OSA patients (n = 105) were recruited from a prospective sleep apnea cohort after polysomnography, with 27 healthy volunteers as the controls. OSA severity was assessed via the apnea-hypopnea index (AHI) and percent night time with SpO2 < 90% (T90).

RESULTS

The serum MMP-9 levels were significantly higher in the OSA patients (AHI ≥ 5/h, 68.8 ± 44.9 ng/mL) than the controls (49.0 ± 18.6 ng/mL, p < 0.001). The MMP-2 levels showed no significant differences. When grouped into T90 quartiles, the MMP-9 levels were higher in the OSA patients in the highest quartile compared to those in the lowest quartile or the controls (90.6 ± 56.3 ng/mL vs. 56.9 ± 31.9 ng/mL, p = 0.022; 90.6 ± 56.3 ng/mL vs. 49.0 ± 18.6 ng/mL, p = 0.002, respectively). The MMP-9 levels correlated with T90 and the AHI (r = 0.36, p < 0.001; r = 0.35, p < 0.001, respectively). Multiple linear regression confirmed a significant association between MMP-9 and T90 after adjusting for body mass index, smoking status, and comorbidities (β = 0.53, p = 0.013). A similar association was observed for the AHI (β = 0.48, p = 0.019).

CONCLUSION

We concluded that serum MMP-9 levels are independently associated with OSA severity, particularly with T90 and the AHI, which suggests that MMP-9 could be a biomarker for OSA severity.

A systematic review with meta-analysis to assess Alzheimer's disease biomarkers in adults with or without obstructive sleep apnoea

INTRODUCTION

The aim was to design a meta-analysis evaluating the positron emission tomography (PET) uptake and cerebrospinal fluid (CSF), circulating levels of amyloid-β (Aβ), and tau proteins OSA group versus control group, as well as the association of these biomarkers with the severity of OSA.

MATERIAL AND METHODS

Four databases were searched until April 17, 2023, without any restrictions. The effect sizes were the standardized mean difference (SMD) along with a 95% confidence interval (CI).

RESULTS

A total of 21 articles were entered into the meta-analysis. The pooled SMDs of the CSF levels in OSA adults compared to controls were: -0.82 (P=0.004) for Aβ42, -1.13 (P<0.001) for Aβ40, 0.17 (P=0.23) for p-tau, 0.04 (P=0.65) for t-tau, 0.08 (P=0.89) for Aβ42/Aβ40 ratio, and 0.81 (P=0.001) for t-tau/Aβ42 ratio. The pooled SMD for the PET uptake of Aβ burden in OSA adults compared to controls was 0.30 (P=0.03). The pooled SMDs of the circulating levels in OSA adults compared to controls were: 0.67 (P=0.002) for Aβ42, 0.11 (P=0.82) for Aβ40, 0.35 (P=0.06) for p-tau, and 1.41(P=0.005) for t-tau. The pooled SMDs for levels of Aβ42, Aβ40, total Aβ, p-tau, t-tau, and Aβ42/Aβ40 ratio in severe OSA adults compared to mild/moderate OSA adults were -0.15 (P=0.33), 0.25 (P=35), 0.04 (P=87), -2.53 (P=0.24), -0.24 (P=0.52), and -0.28 (P=0.30), respectively.

CONCLUSIONS

The results indicated that CSF levels of Aβ42 and Aβ40 in OSA adults were significantly lower, but the CSF level of t-tau/Aβ42 ratio and PET Aβ burden uptake in OSA adults significantly were higher than in controls.

Current Smoking Determines the Levels of Circulating MPO and MMP-9 in Adults with Coronary Artery Disease and Obstructive Sleep Apnea

(1) Background: Obstructive sleep apnea (OSA) is common in patients with coronary artery disease (CAD), in which a rupture of atherosclerotic plaques and oxidative stress play a role in the initiation and progression of the disorder. Circulating levels of myeloperoxidase (MPO), as an oxidative stress marker, as well as matrix metalloproteinase-9 (MMP-9), as a destabilizer of plaques, are known to be elevated in patients with CAD and are associated with worse prognosis. Some studies have suggested that OSA is associated with MPO and MMP-9, but the effect of OSA on these biomarkers in cardiac cohorts is unknown. (2) Aims: We addressed the determinants of high MPO and MMP-9 in a CAD cohort with concomitant OSA. (3) Materials and Methods: The current study was a secondary analysis of the RICCADSA trial that was conducted in Sweden between 2005 and 2013. A total of 502 revascularized CAD patients with OSA (apnea-hypopnea index [AHI] ≥ 15 events/h; n = 391) or no-OSA (AHI < 5 events/h; n = 101), based on a home sleep apnea test, and who had blood samples at baseline were included in the analysis. The patients were dichotomized into a high or low MPO and MMP-9 groups, based on the median cut-off values. (4) Results: The mean age of the participants was 63.9 (±8.6), and 84% of the study cohort were men. Median values of MPO and MMP-9 levels were 116 ng/mL and 269 ng/mL, respectively. In different multivariate linear and logistic regression models, neither OSA nor OSA severity in terms of AHI and oxygenation indices were associated with the high MPO and MMP-9 levels. Current smoking was significantly associated with both high MPO (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.06-2.84; p = 0.030) and high MMP-9 levels (OR 2.41, 95% CI 1.44-4.03; p < 0.001), respectively. Other significant determinants were revealed as beta blocker use (OR 1.81, 95% CI 1.04-3.16; p = 0.036) for high MPO as well as male sex (OR 2.07, 95% CI 1.23-3.50; p = 0.006) and calcium antagonist use (OR 1.91, 95% CI 1.18-3.09; p = 0.008) for high MMP-9 levels. (5) Conclusions: Current smoking, but not OSA, was significantly associated with high MPO and MMP-9 levels in this revascularized CAD cohort. Smoking status should be seriously taken into consideration while evaluating the effects of OSA and its treatment on long-term adverse cardiovascular outcomes in adults with CAD.

Evaluation of Blood Intercellular Adhesion Molecule-1 (ICAM-1) Level in Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Background and objective: Intercellular adhesion molecule-1 (ICAM-1) appears to be an active and important biomarker for decreasing the risk of cardiovascular issues among individuals with obstructive sleep apnea (OSA). Herein, a systematic review and meta-analysis was designed to probe whether plasma/serum ICAM-1levels are different in adults with OSA compared to adults with no OSA, as well as adults with severe OSA compared to adults with mild/moderate OSA. Materials and methods: A thorough and systematic literature search was performed in four databases (PubMed/Medline, Web of Science, Scopus, and Cochrane Library) until 17 July 2022, without any age and sample size restrictions to retrieve the relevant articles. The standardized mean difference (SMD) along with a 95% confidence interval (CI) of plasma/serum of ICAM-1 levels was reported. Analyses, including sensitivity analysis, subgroup analysis, trial sequential analysis, meta-regression, and a funnel plot analysis, were performed in the pooled analysis. Results: A total of 414 records were identified in the databases, and 17 articles including 22 studies were entered into the meta-analysis. The pooled SMD of serum/plasma ICAM-1 levels in adults with OSA compared to controls was 2.00 (95%CI: 1.41, 2.59; p < 0.00001). The pooled SMD of serum/plasma ICAM-1 levels in adults with severe compared to mild/moderate OSA was 3.62 (95%CI: 1.74, 5.51; p = 0.0002). Higher serum/plasma ICAM-1 levels were associated with a higher mean age of controls, higher scores for the apnea-hypopnea index, and with a lower mean age of adults with OSA and with smaller sample sizes. Conclusions: Th results of the present meta-analysis showed that serum/plasma ICAM-1 levels in adults with OSA was higher than serum/plasma ICAM-1 levels in controls. Similarly, serum/plasma ICAM-1 levels in adults with severe OSA were higher compared to serum/plasma ICAM-1 levels of adults with mild or moderate OSA. Therefore, ICAM-1 may be used as an additional diagnostic and therapeutic biomarker in adults with OSA.

Association of matrix metalloproteinase-9 and nitric oxide with hypertension in obstructive sleep apnea

Background

Patients with obstructive sleep apnea (OSA) are more likely to suffer from hypertension. At the same time, the serum levels of matrix metalloproteinase-9 (MMP-9) and nitric oxide (NO) in patients with OSA are also changed in OSA patients. We investigated the correlation between serum levels of MMP-9, NO in patients with OSA and their association with hypertension in those patients, and the effects of continuous positive airway pressure therapy (CPAP) on these serum biomarkers and blood pressure.

Methods

Serum MMP-9 and NO levels and blood pressure of 57 patients with newly diagnosed OSA and 30 controls were measured; among them, 30 patients with moderate to severe OSA underwent 3-month CPAP treatment.

Results

In comparison to the control group, the MMP-9 serum levels were higher (232.8 ± 103.2 ng/ml versus 161.6 ± 56.5 ng/ml, p < .001*), there was no statistical significance difference among serum NO (26.7 ± 9.1 IU/ml versus 31.0 ± 11.7 IU/ml, p = .06), and MMP-9 was negatively correlated to NO, especially in patients with hypertension (r = -.644, p = .02*). MMP-9, NO, and blood pressure were significantly recovered in the patients with OSA after CPAP treatment for 3 months (p < .05*).

Conclusion

The MMP-9 level and the NO level were altered in OSA patients. The relationship between the two especially in patients with hypertension suggests the potential mechanism of OSA-induced hypertension.

Protease Activated Receptor 1 and Its Ligands as Main Regulators of the Regeneration of Peripheral Nerves

In contrast with the brain and spinal cord, peripheral nerves possess a striking ability to regenerate after damage. This characteristic of the peripheral nervous system is mainly due to a specific population of glial cells, the Schwann cells. Schwann cells promptly activate after nerve injury, dedifferentiate assuming a repair phenotype, and assist axon regrowth. In general, tissue injury determines the release of a variety of proteases which, in parallel with the degradation of their specific targets, also activate plasma membrane receptors known as protease-activated receptors (PARs). PAR1, the prototypical member of the PAR family, is also known as thrombin receptor and is present at the Schwann cell plasma membrane. This receptor is emerging as a possible regulator of the pro-regenerative capacity of Schwann cells. Here, we summarize the most recent literature data describing the possible contribution of PAR1 and PAR1-activating proteases in regulating the regeneration of peripheral nerves.

Increased serum levels of cyclophilin a and matrix metalloproteinase-9 are associated with cognitive impairment in patients with obstructive sleep apnea

OBJECTIVES

To investigate the relationship between serum cyclophilin A (CyPA) and matrix metalloproteinase-9 (MMP-9) levels and mild cognitive impairment (MCI) in patients with obstructive sleep apnea (OSA).

METHODS

Study subjects underwent whole-night in-laboratory polysomnography (PSG), and all participants were scored using a neuropsychological scale and peripheral blood samples were collected the next morning. The presence and severity of OSA were assessed with the apnea hypopnea index (AHI), and OSA was defined as AHI ≥5 events/hour. MCI was defined as the MoCA ≤25, and met the revised Mayo Clinic criteria. Serum CyPA and MMP-9 levels were measured with enzyme-linked immunosorbent assays (ELISAs). A univariate analysis and a logistic model were used to assess risk factors for MCI in patients with OSA. A correlation analysis was performed to estimate whether a linear relationship existed between serum CyPA and MMP-9 levels and the severity of cerebral small vessel disease (CSVD) and white matter hyperintensities (WMHs). A linear regression analysis was used to clarify the relationship between serum CyPA and MMP-9 levels and the degree of cognitive impairment in patients with OSA.

RESULTS

The 186 patients who met the criteria for inclusion and exclusion comprised 71 patients with OSA presenting with MCI (OSA + MCI), 73 patients with OSA without MCI (OSA-MCI), and 42 controls. Patients with OSA + MCI presented higher serum CyPA and MMP-9 levels than patients in the OSA-MCI (11.56 ± 4.52 ng/ml vs 9.95 ± 3.63 ng/ml, p = 0.020; 597.71 ± 204.41 ng/ml vs 523.05 ± 205.47 ng/ml, p = 0.030) and control groups (11.56 ± 4.52 ng/ml vs 8.80 ± 3.71 ng/m, p = 0.001; 597.71 ± 204.41 ng/ml vs 490.39 ± 155.07 ng/ml, p = 0.002). The logistic regression analysis revealed that both CyPA (OR: 1.111, 95% CIs: 1.012-1.219, p = 0.027) and MMP-9 levels (OR: 1.003, 95% CIs: 1.000-1.004, p = 0.011) contributed significantly to MCI in patients with OSA. In the OSA + MCI group, positive correlations were observed between serum CyPA and MMP-9 levels with Scheltens scores (r = 0.437, p = 0.000; r = 0.613, p = 0.000, respectively) and total CSVD burden scores (r = 0.318, p = 0.003; r = 0.487, p = 0.000, respectively). Serum CyPA and MMP-9 levels were linearly negatively correlated with mean oxygen saturation during sleep (mean SaO2) (r = -0.595, p = 0.000; r = -0.570, p = 0.000). There was linear correlation between mean SaO2 and MoCA scores by Pearson's correlation coefficient (r = 0.403, p = 0.000). The linear regression analysis revealed negative correlations between serum CyPA and MMP-9 levels and the Montreal Cognitive Assessment (MoCA) scores (r = -0.528, p = 0.000; r = -0.459, p = 0.000, respectively), and serum CyPA levels were negatively correlated with score of cognitive subdomainss, including visuo-executive function, attention and delayed recall. However, serum MMP-9 levels were negatively correlated with score of cognitive subdomains, including visuo-executive function and delayed recall.

CONCLUSIONS

Increased serum levels of CyPA and MMP-9 are associated with MCI in OSA patients and directly related to the severity of CSVD and WMHs. The results suggest that damage to the blood-brain barrier (BBB) may be involved in the early stages of cognitive impairment in patients with OSA.

Ocular Complications of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), the most common form of sleep-disordered breathing, is characterized by repetitive episodes of paused breathing during sleep, which in turn induces transient nocturnal hypoxia and hypercapnia. The high prevalence of OSA and its associated health consequences place a heavy burden on the healthcare system. In particular, the consequent episodic oxygenic desaturation/reoxygenation series and arousals from sleep in patients with OSA have the potential to trigger oxidative stress, elevated systemic inflammatory responses, and autonomic dysfunction with sympathetic activation. Given these adverse side-effects, OSA is highly correlated to many eye diseases that are common in everyday ophthalmic practices. Some of these ocular consequences are reversible, but they may permanently threaten a patient’s vision if not treated appropriately. Here, this article seeks to review the ocular consequences and potential pathophysiologic associations in patients with OSA. Understanding these OSA-related eye diseases may help clinicians provide comprehensive care to their patients.

Matrix metalloproteinase-9 as a messenger in the cross talk between obstructive sleep apnea and comorbid systemic hypertension, cardiac remodeling, and ischemic stroke: a literature review

STUDY OBJECTIVES

OSA is a common sleep disorder. There is a strong link between sleep-related breathing disorders and cardiovascular and cerebrovascular diseases. Matrix metalloproteinase-9 (MMP-9) is a biological marker for extracellular matrix degradation, which plays a significant role in systemic hypertension, myocardial infarction and postmyocardial infarction heart failure, and ischemic stroke. This article reviews MMP-9 as an inflammatory mediator and a potential messenger between OSA and OSA-induced comorbidities.

METHODS

We reviewed the MEDLINE database (PubMed) for publications on MMP-9, OSA, and cardiovascular disease, identifying 1,592 studies and including and reviewing 50 articles for this work.

RESULTS

There is strong evidence that MMP-9 and tissue inhibitor of metalloproteinase-1 levels are elevated in patients with OSA (mainly MMP-9), systemic hypertension, myocardial infarction, and postmyocardial infarction heart failure. Our study showed variable results that could be related to the sample size or to laboratory methodology.

CONCLUSIONS

MMP-9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase-1, are a common denominator in OSA, systemic hypertension, myocardial infarction, and heart failure. This characterization makes MMP-9 a target for developing novel selective inhibitors that can serve as adjuvant therapy in patients with OSA, which may ameliorate the cardiovascular and cerebrovascular mortality associated with OSA.

Elevation of CD40/CD40L Inflammatory Pathway Molecules in Carotid Plaques from Moderate-and-Severe Obstructive Sleep Apnea Patients

A chronic inflammatory process characteristic of obstructive sleep apnea promotes vascular endothelial dysfunction and atherogenesis. This process can lead to destabilization and rupture of cardiovascular plaques, which clinically manifests as an acute coronary syndrome or stroke. The aim of this study was to investigate the inflammatory pathway leading to plaque destabilization in non-to-mild and moderate-to-severe groups of OSA patients. This prospective study involved enrollment of patients scheduled for endarterectomy. A sleep study was performed prior to surgery. Immunohistochemistry was performed on atherosclerotic plaques from carotid arteries obtained during standard open endarterectomy to determine levels of CD40, CD40L receptors, MCP-1, and MMP-9. The 46 patients included 14 controls, 13 with mild, 11 with moderate, and 8 with severe OSA. Increased expression of CD40, CD40L receptors, MCP-1, and MMP-9 were found to be proportionate with OSA severity. However, significant differences among groups were observed only for MCP-1 (p = 0.014). Increased expression of inflammatory markers (CD40, CD40L, MCP-1, MMP-9) is associated with increasing OSA severity. This suggests the CD40-CD4-L inflammatory pathway may contribute to plaque instability and rupture in OSA patients.

Serum matrix metalloproteinase-2 as a predictor of level of hypoxemia and severity of obstructive sleep apnea

PURPOSE

Intermittent hypoxia in obstructive sleep apnea (OSA) resembles ischemia/reperfusion. Oxidative stress during ischemia/reperfusion increases matrix metalloproteinase-2 (MMP-2) activity and leads to adverse cardiovascular consequences in animal models, but there is scarce information about MMP-2 in humans with OSA. The aim of this study was to determine if serum MMP-2 levels of patients with OSA differ from controls and if MMP-2 activity correlates with the severity of OSA and level of hypoxemia.

METHODS

Patients with OSA (n = 124) were recruited from the Sleep Disorders Center (Saskatoon City Hospital, Canada) after in-lab polysomnography (PSG). Controls (n = 26) were subjects referred for PSG who did not have OSA. Severity of OSA was categorized according to American Academy of Sleep Medicine criteria. Level of hypoxemia was expressed as oxygen desaturation index (ODI; 3% desaturation). Gelatin zymography was performed to measure serum MMP-2 activity.

RESULTS

Serum MMP-2 activity was significantly higher in patients with OSA than in controls (p = 0.029). MMP-2 activity in patients with severe OSA was significantly higher than in those with mild/moderate OSA and controls (p = 0.002). Linear regression showed positive associations with MMP-2 activity in serum for AHI (p < 0.001) and ODI (p = 0.003). The associations persisted after adjustment for multiple confounders, including age, sex, BMI, and cardiovascular disease.

CONCLUSIONS

Serum MMP-2 activity was associated with OSA severity, and level of hypoxemia in patients with OSA, suggesting MMP-2 is worth considering as a potential biomarker to be included in future studies on sets of biomarkers for hypoxemic insult in OSA.